Buggy code:
public String getMonitor ( ) { } public boolean isMonitor ( ) { } public void setImplementation ( String value ) { } public String getImplementation ( ) { } public boolean useMD5 ( ) { } public void setMD5 ( boolean truth ) { } public void addEncodedArgument ( String name , String value ) { } public void addEncodedArgument ( String name , String value , String metaData , String contentEncoding ) { } public void addEncodedArgument ( String name , String value , String metaData ) { } public void addNonEncodedArgument ( String name , String value , String metadata ) { } public void addArgument ( String name , String value ) { } public void addArgument ( String name , String value , String metadata ) { } public boolean hasArguments ( ) { } @ Override public void addTestElement ( TestElement el ) { } @ Override public void clearTestElementChildren ( ) { } public void setPort ( int value ) { } public static int getDefaultPort ( String protocol , int port ) { } public int getPortIfSpecified ( ) { } public boolean isProtocolDefaultPort ( ) { } public int getPort ( ) { } public void setDomain ( String value ) { } public String getDomain ( ) { } public void setConnectTimeout ( String value ) { } public int getConnectTimeout ( ) { } public void setResponseTimeout ( String value ) { } public int getResponseTimeout ( ) { } public String getProxyHost ( ) { } public int getProxyPortInt ( ) { } public String getProxyUser ( ) { } public String getProxyPass ( ) { } public void setArguments ( Arguments value ) { } public Arguments getArguments ( ) { } public void setPostBodyRaw ( boolean value ) { } public boolean getPostBodyRaw ( ) { } public void setAuthManager ( AuthManager value ) { } public AuthManager getAuthManager ( ) { } public void setHeaderManager ( HeaderManager value ) { } public HeaderManager getHeaderManager ( ) { } public void setCookieManager ( CookieManager value ) { } public CookieManager getCookieManager ( ) { } public void setCacheManager ( CacheManager value ) { } public CacheManager getCacheManager ( ) { } public boolean isImageParser ( ) { } public void setImageParser ( boolean parseImages ) { } public String getEmbeddedUrlRE ( ) { } public void setEmbeddedUrlRE ( String regex ) { } protected HTTPSampleResult errorResult ( Throwable e , HTTPSampleResult res ) { } private static final String HTTP_PREFIX = ( PROTOCOL_HTTP ) + ":////" ; private static final String HTTPS_PREFIX = ( PROTOCOL_HTTPS ) + ":////" ; private static final boolean SEPARATE_CONTAINER = JMeterUtils . getPropDefault ( "httpsampler.separate.container" , true ) ; public java . net . URL getUrl ( ) throws MalformedURLException { } public String getQueryString ( ) { } public String getQueryString ( String contentEncoding ) { } public void parseArguments ( String queryString , String contentEncoding ) { } public void parseArguments ( String queryString ) { } @ Override public String toString ( ) { } public SampleResult sample ( Entry e ) { } public SampleResult sample ( ) { } protected abstract HTTPSampleResult sample ( java . net . URL u , String method , boolean areFollowingRedirect , int depth ) { } protected HTTPSampleResult downloadPageResources ( HTTPSampleResult res , HTTPSampleResult container , int frameDepth ) { Iterator < java . net . URL > urls = null ; try { final byte [ ] responseData = res . getResponseData ( ) ; if ( ( responseData . length ) > 0 ) { String parserName = getParserClass ( res ) ; if ( parserName != null ) { final HTMLParser parser = ( ( parserName . length ( ) ) > 0 ) ? HTMLParser . getParser ( parserName ) : HTMLParser . getParser ( ) ; <START_BUG> urls = parser . getEmbeddedResourceURLs ( responseData , res . getURL ( ) ) ; <END_BUG> } } } catch ( HTMLParseException e ) { res . addSubResult ( errorResult ( e , res ) ) ; res . setSuccessful ( false ) ; } if ( ( urls != null ) && ( urls . hasNext ( ) ) ) { if ( container == null ) { res . setThreadName ( Thread . currentThread ( ) . getName ( ) ) ; container = new HTTPSampleResult ( res ) ; container . addRawSubResult ( res ) ; } res = container ; String re = getEmbeddedUrlRE ( ) ; Perl5Matcher localMatcher = null ; Pattern pattern = null ; if ( ( re . length ( ) ) > 0 ) { try { pattern = JMeterUtils . getPattern ( re ) ; localMatcher = JMeterUtils . getMatcher ( ) ; } catch ( MalformedCachePatternException e ) { HTTPSamplerBase . log . warn ( ( "Ignoring<seq2seq4repair_space>embedded<seq2seq4repair_space>URL<seq2seq4repair_space>match<seq2seq4repair_space>string:<seq2seq4repair_space>" + ( e . getMessage ( ) ) ) ) ; } } final List < Callable < HTTPSamplerBase . AsynSamplerResultHolder > > liste = new ArrayList < Callable < HTTPSamplerBase . AsynSamplerResultHolder > > ( ) ; while ( urls . hasNext ( ) ) { Object binURL = urls . next ( ) ; try { java . net . URL url = ( ( java . net . URL ) ( binURL ) ) ; if ( url == null ) { HTTPSamplerBase . log . warn ( "Null<seq2seq4repair_space>URL<seq2seq4repair_space>detected<seq2seq4repair_space>(should<seq2seq4repair_space>not<seq2seq4repair_space>happen)" ) ; } else { String urlstr = url . toString ( ) ; String urlStrEnc = encodeSpaces ( urlstr ) ; if ( ! ( urlstr . equals ( urlStrEnc ) ) ) { try { url = new java . net . URL ( urlStrEnc ) ; } catch ( MalformedURLException e ) { res . addSubResult ( errorResult ( new Exception ( ( urlStrEnc + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>a<seq2seq4repair_space>correct<seq2seq4repair_space>URI" ) ) , res ) ) ; res . setSuccessful ( false ) ; continue ;

Fix:
urls = parser . getEmbeddedResourceURLs ( responseData , res . getURL ( ) , res . getDataEncodingWithDefault ( ) ) ;